DURHAM, N.C., March 16 (UPI) -- For baboons, the bacterial makeup of an individual's intestines isn't simply a matter of diet -- it's also about who you know. New research suggests friendships and other close relationships dictate the collection of microbes in the gut.
A team of researchers studied the microbiomes of from two groups of baboons living near Mount Kilimanjaro in Kenya. Their analysis showed that, not surprisingly, that the gut microbes of baboons from the same troop were more similar than from different troops.
Common sense would suggest a family that eats together -- and thus shares a similar diet -- would be more likely to have a similar microbiome.
But the researchers detailed observations and statistical analysis went further, accounting for factors like diet and proximity. Ultimately, scientists were able to show that how much time two baboons spent together was a better predictor of microbiotic similarity than any other factor.
"When baboons groom each other they're combing through each other's fur for parasites, dirt, dead skin," explained study co-author Elizabeth Archie, a biologist at the University of Notre Dame. "Sometimes they pull things off and put them in their mouths,"
"Males and females also spend a lot of time grooming close to the genital area during estrous," added co-author Jenny Tung, a biologist at Duke University.
The findings have implications for the microbial makeup of human biological systems. The microbiome of the gastrointestinal system -- and its role in human health -- has increasingly been the subject of medical research.
If personal relationships dictate the bacterial lineup inside a baboon's guts, it's likely human relationships -- in addition to diet, genetics and other environmental factors -- play a similar role.
"This is another way that social relationships can influence your health," Archie concluded. "Not only are relationships important for the transmission of harmful bacteria like the ones that cause pneumonia or strep throat, but they're important for the transmission of microbes that are harmless or potentially good for you, too."
The new study was published this week in the journal eLife.